Nexperia USA Inc. 74HC161D,653

Overview

74HC161D,653 from Nexperia is a synchronous presettable 4-bit binary counter with asynchronous master reset (MR), internal look-ahead carry, and dual count-enable inputs (CEP/CET) for cascading. It operates from 2.0 V to 6.0 V, delivers up to 48 MHz maximum clock frequency at VCC = 6.0 V, and features positive-edge-triggered clock (CP), parallel load via active-low PE, and terminal count (TC) output synchronized to Q0 pulse width. It is used in digital timing control, address sequencing, and multi-stage counter systems.

For engineers reviewing the 74HC161D,653 datasheet, 74HC161D,653 pinout, 74HC161D,653 application, or 74HC161D,653 equivalent, key selection considerations include its asynchronous reset behavior, TC output timing relationship to Q0, CP-to-TC propagation delay (as low as 20 ns at 6.0 V), dual enable logic for n-bit cascading, and guaranteed operation from –40 °C to +125 °C in SO16 package.

Technical Context

The 74HC161D implements four edge-triggered D-type flip-flops with synchronous counting, parallel loading, and asynchronous clear. Its look-ahead carry architecture enables deterministic propagation of terminal count across cascaded stages without ripple delay penalties.

Counting requires both CEP and CET HIGH; TC asserts only when CET is HIGH and all outputs (Q0–Q3) are HIGH (1111). The TC pulse width matches Q0's HIGH time, enabling direct feed-forward to the next stage's CE input - eliminating external gating in multi-counter chains.

Key Specifications

Pinout & Package

74HC161D,653 is housed in SO16 (SOT109-1) plastic small outline package: 16-pin, 3.9 mm body width, gull-wing leads, JEDEC MS-012 compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-bit synchronous counter applications.

Compared with 74HC161D,653, the 74HC163D lacks true asynchronous reset - limiting use in safety-critical timing paths - while SN74HC161N trades SO16 manufacturability for DIP-16 hand-solderability, impacting thermal performance and PCB density.

Availability

74HC161D,653 is available at Aetrix Electronics and suitable for industrial PLC timing, LED multiplexing control, serial data framing, and test equipment pulse generation requiring stable component supply across extended temperature ranges.

Supply support for 74HC161D,653 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Nexperia is a global semiconductor expert delivering high-performance logic, discrete, and MOSFET solutions with emphasis on reliability, efficiency, and scalability for industrial and automotive markets.

The 74HC161 belongs to Nexperia's HC-series high-speed CMOS logic family, designed for robust digital control in harsh environments - specifically targeting timing-critical applications needing deterministic propagation, wide voltage tolerance, and extended temperature operation.

FAQ

What is the function of the TC (terminal count) output?

The TC output goes HIGH only when the counter reaches 1111 (15 decimal) AND the CET input is HIGH. Its pulse width equals the HIGH time of Q0, making it ideal for directly enabling the next cascaded counter stage without external timing components. TC does not assert during parallel load or reset operations.

Can 74HC161D,653 operate at 3.3 V supply?

Yes - the 74HC161D,653 is fully specified from 2.0 V to 6.0 V, including 3.3 V operation. At VCC = 3.3 V, typical propagation delay is ~30 ns and maximum operating frequency exceeds 30 MHz, with VIH/VIL thresholds scaled proportionally (VIH ≈ 2.1 V min, VIL ≈ 1.35 V max).

How does the dual enable (CEP and CET) improve cascading reliability?

CEP enables internal counting and carry generation, while CET controls TC assertion and feeds forward to the next stage. This separation prevents spurious TC pulses during partial enable states and ensures TC only activates when both local counting readiness (CEP) and upstream permission (CET) are confirmed - eliminating race conditions in multi-chip counter chains.

Is the MR (master reset) input 5 V tolerant when VCC = 3.3 V?

No - MR is not 5 V tolerant. All inputs, including MR, must remain within GND to VCC (0–3.3 V) when operating at 3.3 V. Exceeding VCC risks latch-up or damage. Clamp diodes exist but are rated for transient overvoltage only; sustained >VCC input violates Absolute Maximum Ratings.